Idiopathic Tenosynovitis by Body Region

1. Tenosynovitis of the Biceps Tendon

Tenosynovitis of the biceps tendon is thought to be caused by repeated trauma or wear resulting from bony changes such as osteophytes in the groove portion of the biceps tendon, or by degenerative changes in the biceps tendon itself, and in most cases it occurs due to a combination of factors. According to researchers such as Rathbun and Macnab, the biceps tendon, like the supraspinatus tendon, has poor blood circulation in the critical zone. In particular, when the arm is moved outward, the intra-articular portion of the biceps tendon is compressed by the head of the humerus, reducing blood supply.

Sometimes calcium may be deposited in the biceps tendon. In most cases, calcium deposition appears as a small deposit at the origin of the biceps tendon, and in rare cases, it occurs at the musculotendinous junction located distally in the groove portion of the biceps tendon. Since tenosynovitis of the biceps tendon is often accompanied by rotator cuff disease, if it is judged that symptoms developed in association with rotator cuff disease, treatment should follow that for rotator cuff disease, with restoration of the range of joint motion and recovery of the function of the rotator cuff and the muscles around the elbow joint.

2. Trigger Finger and Thumb

Trigger finger refers to a condition that occurs when a nodule or fusiform swelling develops in the flexor tendon that bends the finger, or when the A1 pulley, a structure located anterior to the neck of the metacarpal bone (palm bone), becomes thickened, making it difficult for the tendon to pass beneath the A1 pulley. As the tendon passes through the affected area when moving the finger, severe friction or pain is felt, and then at some point a sudden popping sound occurs and movement becomes easier. It is named this way because it resembles the action of pulling a trigger.

This condition is very common and mainly occurs in adults over 45 years of age. It is frequently seen in the thumb, ring finger, and middle finger. Usually, no specific cause can be identified, but it can also occur due to repeated friction on the palm from occupations that involve holding tools with handles or steering wheels for long periods, or from sports such as golf. When the tendon catches and then releases, a snapping sound can be felt or heard, and pain is often present as well.

3. De Quervain's Disease

This refers to stenosing tenosynovitis of the abductor pollicis longus tendon and extensor pollicis brevis tendon, which pass through the first compartment of the osteofibrous tunnel formed by the radial styloid process and the extensor retinaculum on the radial side of the wrist. The osteofibrous tunnel in this area is about 1 inch long. It mainly occurs in women between the ages of 30 and 60, and is especially common in late pregnancy or during lactation. Pain and tenderness around the radial styloid process are common symptoms, and radiating pain may also be reported.

If the patient's thumb is flexed and then the wrist is adducted toward the ulnar side (toward the little finger side) to induce tension in the affected tendon, severe pain is reported. In most cases, the cause of the stenosis is repetitive activities that excessively use the hand or wrist joint, and it is considered to occur secondarily as fibrosis of the extensor retinaculum progresses and the fibrous sheath thickens.

4. Tenosynovitis of the Finger Extensor Tendons

Any tendon present on the back of the wrist can be affected by tenosynovitis. In most cases, it is thought that mild inflammation develops in the tendon sheath or tendon due to repeated overuse. However, it can also occur in rheumatoid arthritis and other connective tissue diseases, gout, tumors, infections caused by fungi or bacteria, and congenital deformities of the distal radius.

If such causes are suspected, a definite diagnosis should be made, and once confirmed, firm treatment of the underlying cause should be carried out along with general treatment for tenosynovitis. In cases thought to be caused by repeated overuse, if the condition is mild, only pain and tenderness may be found in the affected compartment.

5. Tenosynovitis of the Extensor Pollicis Longus Tendon

The extensor pollicis longus tendon passes through the third dorsal compartment on the back of the wrist, medial to Lister's tubercle, and tendon rupture is sometimes found in this area. Tendon rupture is thought to occur as a sequela of Colles' fracture (fracture of the wrist joint), infiltration of rheumatoid scar tissue, or in cases where the tendon has been overused and weakened by continuous friction, as in drummer's palsy.

Once the tendon ruptures, it must be repaired or reconstructed surgically, but the outcome of surgery is not uniformly reliable. Therefore, tenosynovitis occurring in the third compartment should be treated early. Treatment can be carried out in a manner similar to De Quervain's disease, but early surgical treatment is preferable in order to prevent tendon rupture. Surgery is preferably performed when symptoms do not improve within 3 to 4 months or when tendon synovial proliferation is confirmed.

6. Tenosynovitis of the Extensor Carpi Ulnaris Tendon

It is not uncommon for the tendon sheath in the sixth compartment of the extensor tendon on the back of the wrist to become irritated. Normally, when the forearm is fully pronated, the extensor carpi ulnaris is located on the dorsal ulnar side behind the ulnar head, and when it is fully supinated, it is located on the volar ulnar side in front of the ulnar head.

The extensor retinaculum consists of two parts: the superficial part, or supratendinous retinaculum, which starts behind the ulnar head and continues into the deep fascia on the anterior side of the wrist. The deep part, also called the restraining part or infratendinous retinaculum, starts behind the ulnar head together with the superficial part and attaches to the ulnar side of the ulnar head.

This tenosynovitis is often chronic and frequently occurs together with anterior subluxation of the tendon. As a mechanism of injury, it has been argued that when the wrist is strongly rotated while in an ulnar-deviated position, the deep retinacular portion attaching to the ulnar side of the distal ulna in front of the tendon among the extensor retinaculum tears, causing subluxation.

So far, I have explained tenosynovitis by body region.

In the next part, we will look at infectious tenosynovitis.

Source: National Health Information Portal, Korea Disease Control and Prevention Agency